Accumulation of lead and zinc concentrations in harmal plant and its effect on plant growth

Abstract Toxic amounts of lead in the environment of plants cause physiological changes and can decrease the growth potential of the plant and in a more severe manner cause the plant to die. Zinc is also an essential nutrient for plants, but excessive accumulation of zinc in plant tissues can alter plant growth stages. In such conditions, susceptible plants are damaged and killed while resistant plants continue to grow and reproduce in these conditions. The aim of this study was to investigate the effect of high concentrations of Pb and Zn on growth, amount of chlorophyll and carotenoid, accumulation and tolerance parameters of harmal.
Material and Harmal plants were treated with concentrations of 0, 5, 10, 25, 50, 100 and 200 mg/l for 14 days and concentrations of 0, 1, 5, 10, 20, 40 and 80 mg/l Zn.
The results showed that increasing lead and zinc concentration decreased shoot length, root length, shoot dry weight and root but increased lead and zinc accumulation in shoot and root. Chlorophyll a, b, total and carotenoid contents also decreased significantly under different concentrations of Pb and Zn compared to the control.
Discussion and Therefore, it can be concluded from this study that harmal has high ability to accumulate and tolerate lead and zinc and can be used for phytoremediation of lead and zinc.